RU2291885C2 - Electroinsulation material - Google Patents

Abstract

FIELD: insulation materials.

SUBSTANCE: invention relates to electroinsulation materials for electric machine windings and aims at creating electroinsulation material possessing high heat resistance (155-180°C), high electrical and mechanical strengths, environmental safety, and which would retain its flexibility over a long storage period. Electroinsulation material according to invention contains mica paper layer, one or two substrate made of glass fabric or from glass fabric and polyester or polyimide film, and binder based on unsaturated nitrogen-containing polyester prepared by condensation of maleic anhydride and polyatomic acids with N-(β-hydroxyethyl)-1,2-amidophthalic acid, N-(β-hydroxyethyl)-1,2-amidoisomethyltetrahydrophtalic acid, N-(β-hydroxyethyl)-1,2-amidoendomethylene trahydrophtalic acid, or mixture thereof (39.6-40.9 wt parts), polymerizable diluent: oligoether acrylate (36.0-48.7 wt parts), and peroxide initiator (0.8-1.0 wt parts), oligoether acrylate including also target additives (2.4-14.0 wt parts), and optionally low-molecular weight epoxy acid as second binder (2.0-12.1 wt parts).

EFFECT: improved performance characteristics.

2 tbl, 13 ex

Description

The invention relates to electrical engineering, namely to electrical insulation materials intended for insulation of the windings of electrical machines.

Known electrical insulation materials containing mica paper, flexible reinforcing substrates and a binder based on thermosetting resins (ed. St. USSR No. 240082, CL N 01 B 3/02, H 01 B 3/40, H 02 K 15/04, 1964 g .; auth. St. RF №2010367 C1, class N 01 B 3/40, 1992; patent of Germany No. 1765565, class 21 C, 2/02, 1972; patent GDR No. 55632, class. 21 C, 2/02, 1967; GDR patent No. 77524, class 21 C, 2/02, 1970; US patent No. 3998983, class 427-374, 1977).

Muscovite or phlogopite mica paper is used as mica paper in such materials, fiberglass or polymer films are used as a substrate, and adhesive compositions based on polyester, epoxy, organosilicon and other resins are used as a binder.

The disadvantage of such materials is their low viability, as a result of which during the manufacturing, transportation and storage they become hard, brittle, unsuitable for insulation of the windings. The low viability of the known materials does not allow them to be stored for more than three months and limits the scope of their application, and also requires additional costs for cooling the materials during transportation and storage (ed. St. USSR No. 794673, class N 01 B 3/04, N 02 K 3/30, H 02 K 15 / 12.1978 g.).

Also known are electrical insulating materials containing a layer of mica paper, fiberglass substrates and a binder based on epoxy resin (ed. St. USSR No. 1474747 A1, CL H 01 3/4, 1987; ed. St. USSR No. 1720096 A1 , CL H 01 B 3/40, 1989).

The disadvantages of such materials include low flexibility and the need to heat them to a temperature of 60 ° C or more when applied to the winding elements. These materials cannot be used for manual isolation, and in the case of machine isolation, winding machines must be equipped with heating devices. In addition, the need for heating during the isolation process leads to an increase in toxicity due to increased release of volatiles.

The well-known electrical insulating material, consisting of mica paper, glued on both sides with fiberglass or polyethylene terephthalate film and fiberglass and impregnated with an epoxy acrylate binder of the following composition, weighted:

epoxy diane resin one hundred endic anhydride 37 oligoester acrylate TGM-3 (triethylene glycol dimethacrylic ester) 137

(TU 16-91 I02.0168.001TU "Impregnated mica bands of grades LSK-110-TPl (SPl, ST, TT), LSEC-5-TPl (SPl), LSK-SS", date of introduction 01.01.2003; technological Regulation 05758799.02206.00198 "Impregnated mica tape of grades LSK-110-TPL (SPl, ST, TT)", approved on May 30, 2002 - analogue.

This binder belongs to the group of unsaturated polyesters, because When the epoxy resin and unsaturated endic anhydride react, an unsaturated polyester is formed. In this case, the active double bonds of the endic anhydride during the curing process are copolymerized with the methacrylate groups of oligoester acrylate. In this binder, the oligoester acrylate TGM-3 is a polymerization diluent. When the binder cures, a "crosslinked" unsaturated polyester is formed.

The use of this binder allows to obtain impregnated mica belts with a sufficiently high flexibility. However, the heat resistance of such materials does not exceed 130 ° C, and their dielectric characteristics at operating temperature are not high.

The above disadvantages are mainly determined by the properties of the binders. By composition, the closest to the proposed one is a binder based on an unsaturated nitrogen-containing polyester, a polymerization diluent and a peroxide initiator, into which an epoxy resin has been introduced to increase adhesive properties (ed. St. USSR No. 294839, class C 08 g 17/14, 1971 - prototype). However, it is not suitable for producing glass mica tapes, because due to its chemical nature, it does not provide the necessary flexibility, being a material of the "hard" type.

The aim of the invention is the creation of an insulating material with high heat resistance, electrical and mechanical strength, environmental safety and maintaining flexibility for a long shelf life.

To achieve this, the invention provides an electrical insulating material comprising a layer of mica paper, one or two substrates of fiberglass or fiberglass and a polyester or polyimide film and a binder based on an unsaturated polyester, a polymerization diluent, a peroxide initiator, including an unsaturated nitrogen-containing polyester obtained by polycondensation of maleic anideic anhydride polyols with N - (β-hydroxyethyl) -1,2-amidophthalic, N- (β-hydroxyethyl) -1,2-amidoisomethyltetrahydrophthalic, N- (β-hydroxy yl) -1,2-amidoendometilentetra gidroftalevoy acids or mixtures thereof; polymerization diluent - oligoester acrylate; target additives and, possibly, low molecular weight epoxy resin as a second binder in the following ratio of components, parts by weight:

unsaturated nitrogen-containing polyester 39.6-40.9 polymerization diluent - oligoester acrylate 36.0-48.7 targeted supplements 2.4-14.0 including second binder 2.0-12.1 peroxide initiator 0.8-1.0

As polyhydric alcohols, diethylene glycol (binder No. 1) or tris - ((β-hydroxyethyl) -isocyanurate (binder No. 2) are used. Triethylene glycol; 1,2-propylene glycol; 2,2'-dimethylolpropane ( neopentyl glycol); 1,1,1-trimethylolpropane (ethriol) and 1,1,1-trimethylol ethane (metriol). In this case, difunctional alcohols can be used for equimolar replacement of diethylene glycol in binder No. 1, and trifunctional alcohols in binder No. 2.

The polymerization diluent oligoether acrylate is mainly TGM-3 (triethylene glycol dimethacrylic ester), MGF-1 oligoester acrylates (α, ω-methacryl (bis-ethylene glycol) phthalate), MGF-9 (α, ω (bis-triethylene glycol) phthalate) and MEG (ethylene glycol monomethacrylic ester) or mixtures thereof.

To increase the heat resistance of the compound and, accordingly, the heat resistance of the insulating material, part of the polymerization diluent - oligoester acrylate - can be replaced by allyl ethers of polycarboxylic acids, which can be used diallyl phthalate or isophthalate and triallyl cyanurate or isocyanurate.

Targeted additives may include peroxide initiators, radical polymerization accelerators and inhibitors, latent catalysts, adhesion promoters, and the like. commonly used additives, as well as low molecular weight epoxy.

The binder according to the invention provides flexibility and environmental safety to the insulating material, preserves its technological properties for at least 6 months and provides high dielectric and mechanical insulation properties at operating temperatures of 155-180 ° C, allowing it to be used in the form of tapes or sheets for continuous or sleeve winding insulation of electrical machines.

Muscovite or phlogopite paper with a surface density of 50 to 160 g / m ^{2 is} used as mica paper in the insulating material. A glass fabric with a surface density of 25 to 80 g / m ² and a polyethylene terephthalate film of 0.008 to 0.02 mm or polyimide thickness from 0.03 to 0.04 mm. Instead of polyethylene terephthalate, other polyester films can be used, for example polyethylene naphthalate or polycarbonate.

The insulating material is made on a horizontal impregnation machine with two drying chambers in two stages. Finished electrical insulation material is fed to the receiving mechanism and wound into a roll. If necessary, the roll can be cut into rollers.

Examples of a binder.

Binder number 1.

15.7 isomethyltetrahydrophthalic anhydride was placed in the reactor (wt.h). The stirrer is turned on and 6.0 monoethanolamine is charged slowly in portions (in order to avoid reaction mass ejection) in portions in 1-2 hours so that the temperature in the mass does not rise above (120 ± 2) ° С due to the exothermicity of the anhydride reaction and monoethanolamine. Thus obtained N- (β-hydroxyethyl) -1,2-amidoisomethyltetrahydrophthalic acid is heated for 1.0-1.5 hours to (180 ± 5) ° C and kept at this temperature for 2-3 hours until an acid number of ≤5 is reached mg KOH / g Heating is turned off, the reaction mass is cooled to (75 ± 5) ° C and 12.0 maleic anhydride, 9.1 diethylene glycol, 0.05 hydroquinone, 0.05 thiuram D and 0.08 tetra-butoxy titanium are charged. Then turn on the heating and the temperature is raised to 180-185 ° C. The polycondensation is carried out at this temperature until the acid number of 35-40 mg KOH / g is reached. Thus obtained nitrogen-containing unsaturated polyester in an amount of 40.9 is cooled to 120-130 ° C and poured into the mixer under a layer of previously inhibited 0.05 benzoquinone 36.0 TGM-3 oligoester acrylate. The solution is cooled to 20-30 ° C and loaded with 0.82 ZhK-12 lead-manganese desiccant, stirred for 0.5-1 h until uniform, then a 2% 50% solution of dicumyl peroxide in dibutyl phthalate is introduced and again mixed in within 0.5-1.0 hours

Binder number 2.

16.2 isomethyltetrahydrophthalic anhydride is placed (parts by weight) in the reactor. Turn on the stirrer, which runs until the end of the process. In a weak stream of inert gas in portions (to prevent the reaction mass from escaping from the reactor), at first slowly and then faster load 6.2 monoethanolamine so that the temperature in the mass does not rise above (120 ± 2) ° C due to the exothermic reaction of the anhydride and monoethanolamine then they turn on the heating of the reactor and increase the temperature to (180 ± 5) ° C in 1.0-1.5 hours. Heating is turned off when the condensate ceases to be distilled off from the reaction mass and the acid number of the product of cyclodehydration of the initially formed N- (β-hydroxyethyl ) -1,2-amidoisomet iltetrahydrophthalic acid will not exceed 5 mg KOH / g.

The reaction mass is cooled to (75 ± 5) ° C and 9.5 maleic anhydride, 0.05 hydroquinone, 0.05 tetrabutoxy titanium and 0.05 thiuram D. are added to it. The temperature is raised to 110-120 ° C and maintained at 1.0 -1.1 hours. After that, 9.6 tris- (β-hydroxyethyl) isocyanurate is charged, the temperature is raised to 180-185 ° C in 1.0-1.5 hours.

Polycondensation is carried out at this temperature to an acid number (40 ± 3) mg KOH / g. The resulting unsaturated nitrogen-containing polyester in an amount of 39.6 is cooled to 140-145 ° C and poured into a mixer with a stirrer, where there is 48.7 TGM-3 oligoester acrylate, previously inhibited by 0.3 benzoquinone. The solution was stirred for 0.5 hours. Then, at 40-50 ° C., 12.1 ED-22 epoxy resins, 0.35 tetrabutoxy titanium and 0.5 ZhK-12 desiccants were charged and mixed for another 0.5 hours. 2% 50% solution of dicumyl peroxide in dibutyl phthalate and again stirred for 0.5-1.0 hours

Examples of obtaining insulating material.

Example 1

Stage 1 Fiberglass with a surface density of 27 g / m ^{2 is} impregnated in a bath containing a solution of natural rubber in toluene with a concentration of 2.7%, mica paper based on muscovite with a surface density of 50 g / m ^{2 is} continuously placed on the impregnated fiberglass, and the resulting glass mica is fed in the first drying chamber with a temperature of 100-130 ° C. From the drying chamber, the glass mica is fed to the receiving mechanism and wound into a roll.

2 stage. The glass mica web roll is dispensed from the tempering mechanism to an impregnation unit containing a binder for impregnation based on an unsaturated nitrogen-containing polyester, a polymerization diluent, and target additives: a free radical initiator, inhibitor, and accelerator (binder No. 1).

The impregnated glass mica cloth enters the first drying chamber at a temperature of 30-60 ° C and at the outlet of the drying chamber is combined with a 0.01 mm thick polyethylene terephthalate film with a layer of EP-934C epoxy-polyester varnish applied to the inner surface.

Before combining, the film was varnished and dried in a second drying chamber at a temperature of 30-40 ° C.

Finished electrical insulation material is fed to the receiving mechanism and wound into a roll.

The binder content in the finished insulating material is from 25 to 35 wt.%, The electric strength is not less than 50 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 2

Stage 1 Fiberglass with a surface density of 38 g / m ^{2 is} impregnated in a bath containing a solution of natural rubber in toluene with a concentration of 2.7%, mica paper based on muscovite with a surface density of 60 g / m ^{2 is} continuously placed on the impregnated fiberglass, and the resulting glass mica is fed in the first drying chamber with a temperature of 100-130 ° C.

From the drying chamber, the glass mica is fed to the receiving mechanism and wound into a roll.

2 stage. The technological process is similar to the 2 stages of example 1.

The binder content in the finished insulating material is from 25 to 35 wt.%, The electric strength is not less than 45 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 3

Stage 1 Fiberglass fabric with a surface density of 45 g / m ^{2 is} impregnated in a bath containing a solution in natural rubber toluene with a concentration of 2.7%, mica paper based on muscovite with a surface density of 70 g / m ^{2 is} continuously placed on the impregnated glass fabric, and the resulting glass mica film is supplied in the first drying chamber with a temperature of 100-130 ° C.

From the drying chamber, the glass mica is fed to the receiving mechanism and wound into a roll.

2 stage. The technological process is similar to the 2 stages of example 1.

The binder content in the finished insulating material is from 25 to 35 wt.%, The electric strength is not less than 40 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 4

Stage 1 The technological process is similar to stage 1 of example 1.

2 stage. A roll of glass mica from the tempering mechanism is sent to an impregnation unit containing a binder for impregnation based on an unsaturated nitrogen-containing polyester, a polymerization diluent and target additives: a free radical initiator, an inhibitor, an accelerator, a latent catalyst - tetrabutoxy titanium and ED-22 epoxy resin (ED-22).

The impregnated glass mica cloth enters the first drying chamber with a temperature of 30-60 ° C and at the outlet of the drying chamber is combined with a 0.03 mm thick polyimide film with a layer of epoxy-polyester varnish EP-934C applied to the inner surface.

Before combining, the film was varnished and dried in a second drying chamber at a temperature of 30-40 ° C.

Finished electrical insulation material is fed to the receiving mechanism and wound into a roll.

The binder content in the finished insulating material is from 25 to 35 wt.%, The electric strength is not less than 50 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 180 ° C.

Example 5

Stage 1 The technological process is similar to stage 1 of example 2.

2 stage. The process is similar to stage 2 of example 4.

The binder content in the finished insulating material is from 25 to 35 wt.%, The electric strength is not less than 45 kV / mm, the dielectric loss tangent is not more than 0.25 at a temperature of 180 ° C.

Example 6

Stage 1 Fiberglass fabrics with a surface density of 38 g / m ² and 45 g / m ^{2 are} impregnated in the lower and upper baths of the impregnation unit of the machine, respectively, containing a solution of natural rubber in toluene with a concentration of 2.7%. The impregnated fiberglass from the lower bath is combined with muscovite-based mica paper with a surface density of 70 g / m ² , the impregnated fiberglass from the upper bath is placed on the mica paper from above, and the resulting glass mica is fed into the first drying chamber with a temperature of 100-130 ° C.

From the drying chamber, the glass mica is fed to the receiving mechanism and wound into a roll.

2 stage. A glass mica web roll is dispensed from the tempering mechanism to an impregnation unit containing a binder No. 2.

The impregnated glass mica cloth enters the first drying chamber with a temperature of 30-60 ° C.

Finished electrical insulation material is fed to the receiving mechanism and wound into a roll.

The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 25 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 7

Stage 1 The technological process is similar to stage 1 of Example 6. In this case, two substrates use fiberglass with a surface density of 45 g / m ² and mica paper based on muscovite with a surface density of 70 g / m ² .

2 stage. The technological process is similar to the 2 stages of Example 6. The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 20 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 8

Stage 1 The technological process is similar to the 1st stage of Example 6. In this case, glass cloth with a surface density of 45 g / m ² and mica paper based on muscovite with a surface density of 90 g / m are used as two substrates.

2 stage. The technological process is similar to the 2 stages of Example 6. The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 18 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 9

Stage 1 The technological process is similar to the 1st stage of Example 6. In this case, glass cloth with a surface density of 45 g / m ² and mica paper based on muscovite with a surface density of 120 g / m ² are used as two substrates.

2 stage. The technological process is similar to the 2 stages of Example 6. The binder content in the finished insulating material is from 35 to 45 wt.%, The electric strength is not less than 30 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 155 ° C.

Example 10

Stage 1 The technological process is similar to stage 1 of example 6.

2 stage. A glass mica web roll is dispensed from the tempering mechanism to an impregnation unit containing a binder No. 2.

The impregnated glass mica cloth enters the first drying chamber with a temperature of 30-60 ° C.

Finished electrical insulation material is fed to the receiving mechanism and wound into a roll.

The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 25 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 180 ° C.

Example 11

Stage 1 The technological process is similar to stage 1 of example 7.

2 stage. The technological process is similar to the 2 stages of Example 10. The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 20 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 180 ° C.

Example 12

Stage 1 The technological process is similar to stage 1 of example 8.

2 stage. The technological process is similar to the 2 stages of Example 10. The binder content in the finished insulating material is from 30 to 40 wt.%, The electric strength is not less than 18 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 180 ° C.

Example 13

Stage 1 The technological process is similar to stage 1 of example 9.

2 stage. The technological process is similar to the 2 stages of Example 10. The binder content in the finished insulating material is from 35 to 45 wt.%, The electric strength is not less than 30 kV / mm, the dielectric loss tangent of the pressed insulation is not more than 0.25 at a temperature of 180 ° C.

The characteristics of electrical insulation materials according to examples 1-13 are presented in tables 1 and 2.

Table 1 Characteristic The proposed electrical insulation material (EIM) for examples: Known EIM (analogue) one 2 3 four 5 Nominal thickness mm 0.08 0.10 0.13 0.10 0.13 0.13 Average electric strength, kV / mm, not less fifty 45 40 fifty 45 thirty Specific breaking load under tension, N / mm, not less 70 120 150 80 one hundred 120 The content of the binder, wt.% 25-35 25-35 25-35 25-35 25-35 25-35 Warranty period of storage at a temperature of 15-35 ° C, months. 6 6 6 6 6 3 Heat resistance class, ° С 155 (F) 155 (F) 155 (F) 180 (H) 180 (N) 130 (B) Dielectric loss tangent at temperature: 155 ° C 0.25 0.25 0.25 - - - 180 ° C - - - 0.25 0.25 -

table 2 Characteristic The proposed electrical insulation material (EIM) for examples: Famous EIM 6 7 8 9 10 eleven 12 13 (analog) Nominal thickness mm 0.13 0.15 0.17 0.20 0.13 0.15 0.17 0.20 0.15 Average electric strength, kV / mm, not less 25 twenty eighteen thirty 25 twenty eighteen thirty eighteen Specific breaking load under tension, N / mm, not less 240 240 240 240 240 240 240 240 240 The content of the binder, wt.% 30-40 30-40 30-40 35-45 30-40 30-40 30-40 35-45 30-40 Warranty period of storage at a temperature of 15-35 ° C, months. 6 6 6 6 6 6 6 6 3 Heat resistance class, ° С 155 (F) 155 (F) 155 (F) 155 (F) 180 (H) 180 (H) 180 (H) 180 (H) 130 (B) Dielectric loss tangent at temperature: 155 ° C 0.25 0.25 0.25 0.25 - - - - - 180 ° C - - - - 0.25 0.25 0.25 0.25 -

Claims (1)

An insulating material containing a layer of mica paper, one or two substrates of fiberglass or fiberglass and a polyester or polyimide film and a binder based on an unsaturated polyester, a polymerization diluent and a peroxide initiator, characterized in that the binder contains an unsaturated nitrogen-containing polyester obtained by polycondensation of maleate and maleate polyamide alcohols with N- (β-hydroxyethyl) -1,2-amidophthalic, N- (β-hydroxyethyl) -1,2-amidoisomethyltetrahydrophthalic, N- (β-hydroxyethyl) -1,2-amidoendomethylene hydrophthalic acids or mixtures thereof, a polymerization diluent - oligoester acrylate, target additives and, possibly, low molecular weight epoxy resin as a second binder, in the following ratio, wt.h .: Unsaturated Nitrogen-Containing Polyester 39.6-40.9 Active diluent - oligoester acrylate 36.0-48.7 Targeted Supplements 2.4-14.0 including Second binder 2.0-12.1 Peroxide Initiator 0.8-1.0